cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A346590 Decimal expansion of lim_{n->infinity} A262957(n)/A263295(n).

Original entry on oeis.org

5, 7, 6, 6, 3, 3, 3, 8, 9, 7, 3, 0, 1, 8, 4, 3, 9, 2, 3, 9, 7, 8, 9, 1, 7, 4, 9, 7, 8, 2, 9, 1, 3, 9, 2, 5, 7, 9, 6, 1, 4, 9, 4, 3, 5, 2, 7, 5, 7, 1, 0, 8, 3, 9, 8, 4, 1, 1, 0, 4, 1, 9, 1, 8, 0, 7, 6, 4, 8, 3, 5, 4, 4, 0, 1, 2, 4, 4, 0, 2, 0, 2, 0, 3, 1, 8, 2, 2, 6, 4
Offset: 0

Views

Author

Hugo Pfoertner, Jul 25 2021

Keywords

Comments

See A262957 for more information and references.

Examples

			0.5766333897301843923978917497829139257961494352757108398411...
		

Crossrefs

A263295 Denominators of the n-th iteration of the alternating continued fraction formed from the positive integers, starting with (1 - ...).

Original entry on oeis.org

3, 5, 33, 111, 933, 4913, 50585, 364717, 4460647, 40920133, 580574377, 6472209467, 104581586665, 1373040648769, 24902871413201, 376386726269561, 7573128424949291, 129519388933667493, 2863373356440803473, 54670305859684290279, 1317404009250178503245
Offset: 1

Views

Author

Mohamed Sabba, Nov 20 2015

Keywords

Comments

As n->inf, A262957(n)/a(n) converges to 0.57663338973018...; this number has a surprisingly elegant standard continued fraction representation: [0; 1, 1, 2, 1, 3, 4, 1, 5, 6, 1, 7, 8, ...].

Examples

			(1-1/(2+1)) = 2/3, so a(1) = 3;
(1-1/(2+1/(3-1))) = 3/5, so a(2) = 5;
(1-1/(2+1/(3-1/(4+1)))) = 19/33, so a(3) = 33;
(1-1/(2+1/(3-1/(4+1/(5-1))))) = 64/111, so a(4) = 111.
		

Crossrefs

Same principle as A244279 and A244280 - except here we begin with subtraction rather than addition.
Cf. A262957 (numerators).

Programs

  • PARI
    a(n) = if(n%2==0, s=-1, s=1); t=1; while(n>0, t=n+1+s/t; n--; s=-s); denominator(t=1/t)
    vector(30, n, a(n)) \\ corrected by Mohammed Sabba, Dec 22 2015

Extensions

More terms from Mohamed Sabba, Dec 22 2015
Showing 1-2 of 2 results.